WO2025215688A1

WO2025215688A1 - Method for automatically adjusting a wire rolling process and rolling apparatus

Info

Publication number: WO2025215688A1
Application number: PCT/IT2025/050088
Authority: WO
Inventors: Luca DEORI; Matteo DROMEDARI; Ivan Rossi; Alberto RUPOLI; Daniele Donati; Aitor BILBAO
Original assignee: Schnell SpA
Current assignee: Schnell SpA
Priority date: 2024-04-11
Filing date: 2025-04-10
Publication date: 2025-10-16
Anticipated expiration: 2026-10-11

Abstract

The method for automatically adjusting a rolling process for metal wires comprises the step of feeding along a rolling direction (L) a metal wire (F) through a rolling apparatus (1) comprising an inlet station (S1) and an outlet station (S2), a plurality of rolling cassettes (2_n, 2_i), each comprising at least one group (21, 22) of rolling wheels (20), defining between them a passage for the wire (F), at least one drive member being connected to the rolling wheels (20) to move them, so as to vary the width of the passage. The plurality of rolling cassettes (2_n, 2_i) is interposed between the inlet station (S1) and the outlet station (S2) to reduce the wire diameter (F) from an inlet diameter (D_in) to an outlet diameter (D_out).

Description

METHOD FOR AUTOMATICALLY ADJUSTING A WIRE ROLLING PROCESS AND ROLLING APPARATUS Technical field

[01] The present invention relates to a method for automatically adjusting a rolling process, particularly cold rolling, for wire as well as a rolling apparatus.

Prior art

[02] Plants are known to produce wire, particularly ribbed wire, by cold-rolling. In particular, in the case of bars or wires to be produced in coil or reel, the rolling process is employed not only to define their dimensions and surface finish, but also to increase the mechanical properties of the product by surface work hardening.

[03] Particularly in the field of manufacturing improved adhesion steel wire for construction, it is important to monitor the geometric dimensions of the wire for reasons of economy and production efficiency.

[04] Improved adhesion steel wires, in particular, are characterized by surface ribs that define a very complex, potentially variable geometry that is difficult to detect, especially continuously.

[05] More precisely, the cold-rolling process to obtain this type of wire transforms a smooth wire having a variable initial diameter into a ribbed wire with a reduced, calibrated final diameter. At the end of the process, the wire is usually wound into a coil. The final diameter is so-called "nominal" or "equivalent," as it represents the diameter of a smooth wire, of regular cylindrical cross-section, equating in weight to the ribbed wire obtained by rolling.

[06] In fact, the cross section of the wire produced has an irregular shape due to the presence of more or less pronounced ribs and ribbing on the outer surface.

[07] As is well known, diameter reduction and rib generation is accomplished by rolling cassettes comprising rolling wheels designed to exert a compressive action on the advancing wire. More specifically, a rolling cassette may comprise one or more groups of rolling wheels. Each group comprises at least two or more, preferably three, wheels angularly distributed around a respective wire passage section, arranged at a radial distance such that the outer surface of the wire is tangentially engaged, on respective surface portions, to reduce the outer diameter of the wire and/or to imprint the desired shape.

[08] The rolling process can take place in one or more steps, each involving a specific rolling cassette. For example, a rolling cassette may comprise three in-feed wheels and three out-feed wheels, which engage the wire to be rolled in advance, at stations spaced along the rolling line. [09] The wire is then passed through one or more rolling cassettes by the dragging action, exerted by a drawing unit, preferably arranged downstream of each cassette, according to a rolling direction.

[10] In machines of the known type, usually each rolling cassette is manually adjusted by an experienced operator, before starting the rolling process, so as to distribute the total reduction to be imposed on the material, among the various steps of the process.

[11] Several process parameters, however, can affect the rolling result.

[12] For example, a wear and tear on the rolling wheels, but also changes in the wire feed speed as a result of acceleration or deceleration phases of the process, as well as changes in temperature or mechanical characteristics of the material constituting the wire, can alter the compressive action on the material, adversely affecting the accuracy of the rolling result. In addition, manual adjustment on individual rolling cassettes may also be incorrect.

[13] It should be borne in mind that the rolling wheels do not act on the entire outer circumference of the wire, but on spaced circumferential portions, which are then interspersed with areas free to deformation, where axial ribbing is generated that further contributes to giving the wire an irregular shape. For this reason, too, the final geometry of the product may be out of tolerance.

[14] In contrast to smooth wires, for which it is instead possible to continuously monitor the rolling result by detecting the external geometry of the wire by direct methods, e.g., vision, contact or noncontact, in the case of improved adhesion wires it can be difficult, if not costly, to employ the same methods because of their complex external geometry and the movement imposed on the wire itself.

[15] Therefore, as a result of this complexity, the detection methods used involve, for improved adhesion wires, proceeding with an "indirect" type of discrete measurement, based on the detection of the weight of a portion of wire of known length, specially taken from the final product, and the calculation of the aforementioned "nominal diameter" or "equivalent" determined for this portion. As anticipated earlier, the nominal diameter, also referred to in the regulations, corresponds to the diameter of a perfectly cylindrical smooth wire, equating in weight to the wire produced.

[16] Since, as explained earlier, the dimensions of the final product may vary during the rolling process, continuous measurements would be desirable to ensure that the entire production meets dimensional requirements. However, this is not possible with known indirect methods, since each measurement would require stopping the coil being formed in order to take a wire sample. However, if sampling is done only at the completion of a roll of material, there is a risk that the entire roll produced would have to be discarded. In any case, this sampling allows an extremely partial control of the wire produced, with no guarantee of the quality of the material generated during the formation of the coil itself.

[17] In addition, even the interruption of the production process for sample taking at the end of the reel is already a problem, as it reduces the productivity of the process.

[18] Therefore, there is a need to accurately determine the nominal diameter of the rolled wire without having to interrupt the process and/or without having to perform the measurement on the finished product.

[19] In addition, if the parameters of the production process vary, the actual reduction achieved at the output of the individual rolling cassette may be different from that originally set by manual adjustment. In such a case, excessive reduction can also lead to wire breakage.

[20] With multiple rolling cassettes, that is, in so-called "multi-step" processes, it is important to prevent excessive reduction from occurring in any of the rolling steps. In practice, if the total reduction imposed on the wire is the desired one, but the rolling process is not properly distributed among the rolling cassettes, the wire may equally break, thus forcing production to be stopped and the product discarded.

[21] In the known apparatus, there is an automatic system for adjusting the speed of each step, achieved by using so-called "dancers," which act by adjusting process speeds between steps as a result of changes occurring in the process itself.

[22] Each "dancer" is realized by means of a deflector roller, borne by a tilting arm and arranged along the wire path, so as to engage it. The automatic tilting of the arm, for example, realized by the action of elastic means of contrast, allows the wire path to be changed, in order to adjust the speed of the wire to the variation of the process parameters, mentioned above.

[23] Such automatic adjustment, however, can only occur within certain limits and, in any case, does not allow for effective control over the outcome of the process.

[24] Known apparatuses, which implements regulation by means of the aforementioned "dancer," do not provide satisfactory control during the rolling process over the actions to which the wire is subjected. Therefore, to prevent the wire from breaking, if, even in one section of the process, tensions and/or speeds reach excessive levels, known apparatuses usually operate below maximum performance in terms of speed and productivity.

[25] Patent application W02014/184109 discloses a method and apparatus for determining the molding quality of a profiled bar material.

[26] Therefore, there is a need to precisely adjust the steps of the process to avoid product breakage.

Disclosure of the invention

[27] The task of the present invention is to solve the above-mentioned problems by devising a method for automatically adjusting a rolling process for metal wires, enabling continuous and effective automatic adjustment of the process.

[28] Another purpose of the present invention is to provide a rolling apparatus, which is of simple constructional and functional design, equipped with safe and reliable use, and of relatively low cost.

[29] The above-mentioned purposes are achieved, according to the present invention, by the method for automatically adjusting a rolling process for wire according to claim 1 , as well as by the rolling apparatus according to claim 7.

[30] In a so-called "multi-step" process, that is, in which the processing on the wire is distributed in several stages or processing steps, the method according to the invention involves feeding the wire through a rolling apparatus along a rolling direction.

[31] The rolling apparatus comprises an inlet station and an outlet station, a plurality of rolling cassettes, each comprising at least one set of rolling wheels, defining a wire passage between them.

[32] Such rolling wheels can be arranged around the longitudinal axis of the advancing wire along the rolling direction to engage it at a respective section and impart permanent deformation on it.

[33] For at least one of the above-mentioned rolling cassettes, at least one drive member is connected to the rolling wheels to move them to vary the width of the said passage. Where there is a plurality of rolling wheel sets for a rolling cassette, a plurality of drive members capable of moving the same wheels to vary the width of the passage for the wire, which can also be operated independently, can be provided.

[34] The plurality of rolling cassettes is interposed between the inlet station and the outlet station to reduce the diameter of the wire from an input diameter to an output diameter through at least one intermediate diameter between one process step and a subsequent step. In the case of a ribbed wire, the outlet diameter is intended to be "nominal" or "equivalent," i.e., corresponding to the diameter of a smooth wire of regular cylindrical cross-section, equating in weight.

[35] In essence, the inlet station may comprise a wire engagement zone in the first set of rolling wheels of the first of the rolling cassettes in succession along the same rolling direction.

[36] Likewise, the exit station may comprise a wire engagement zone in the last set of rolling wheels of the last of the rolling cassettes in succession along the same rolling direction.

[37] The above-mentioned plurality of rolling cassettes comprises a terminal rolling cassette or terminal step, i.e., the last cassette in the succession, at the exit from which the wire has the above-mentioned exit diameter, and at least one intermediate rolling cassette or intermediate step which, starting from the inlet station, precedes the terminal rolling cassette along the rolling direction. In the case of two rolling cassettes, the intermediate cassette coincides with the first cassette along the rolling direction.

[38] The apparatus also comprises an end drawing unit and, respectively, at least one intermediate drawing unit, each being driven by a respective drive member to drive the wire forward in the rolling direction along a respective rolling cassette.

[39] A sensor device, for example, associated directly or indirectly with the drive member of an intermediate drawing unit, is also provided to detect an intermediate datum that can be related to the output speed or of the intermediate percentage reduction of the drawn wire in a respective intermediate step of the rolling process.

[40] Specifically, the sensor device can be configured to detect a figure indicative of the wire drawing speed through the rotation speed of the drive wheel of the aforementioned drawing unit.

[41] Alternatively, the sensor device, particularly if of the type of a strain gauge, can detect a force applied to the means of support of the same drive member, or rolling cassettes or other support, such as of a "dancer" type compensating device, capable of compensating and/or adjusting the speed of the wire in the process. In addition or alternatively, the sensor device can detect the value of the current drawn by the same drive member.

[42] The method involves detecting and/or inputting by means of a detection and/or input assembly at least one input data related to the wire, specifically the wire input diameter.

[43] The method also involves detecting and/or inputting by means of a sensing and/or input group at least one output data, specifically the output diameter of the wire.

[44] The method involves setting up an apparatus processing unit.

[45] The method then preferably involves calculating a value of the total percentage reduction of the wire, based on the data collected and/or entered, by means of the processing unit, or entering it directly to the said processing unit.

[46] Thus, the processing unit can calculate an intermediate percent reduction reference value for at least one intermediate step, distributing the total percent reduction value appropriately, or intermediate diameter reference values for at least one intermediate step.

[47] The method then preferably involves calculating, on the basis of the detected intermediate datum mentioned above, as well as the detection, referring to the same instant, of the wire exit velocity, the wire input diameter in at least one intermediate step of the process, according to a formula based on the principle of continuity of wire flow, that is, weight per unit length and per unit time, through each section of the apparatus.

[48] Preferably, the method involves calculating the actual value of the intermediate percentage reduction for each intermediate step.

[49] With the calculation of the wire input diameter in the intermediate step, the actual value of the intermediate percentage reduction for the intermediate step can be calculated by the processing unit.

[50] The processing unit then makes a comparison between the reference value and the calculated actual value, preferably for intermediate percent reduction or intermediate diameter.

[51] If there is a deviation, the processing unit sends an adjustment command, preferably to the motor associated with at least one set of intermediate step rolling wheels, to bring the actual value back to the reference value, such as intermediate percent reduction.

[52] Alternatively or additionally, the processing unit sends a control command to the terminal drawing unit and/or at least one intermediate drawing unit to adjust the wire speed in the upstream to downstream steps of the process. For this purpose, the processing unit may preferably send an adjustment command to at least one drive member of a drawing unit.

[53] Preferably, the method involves continuously processing, through the processing unit, the actual diameter of the incoming or outgoing wire for at least one and, preferably, each rolling cassette, terminal or intermediate.

[54] Advantageously, the method allows continuous monitoring of the diameter of the wire output, particularly of ribbed wire.

[55] The method can also allow the wire reduction ratio for each rolling step to be processed and monitored, preferably continuously.

[56] More specifically, the method in question may allow for the preferably continuous processing of the diameter of the incoming wire, particularly at each rolling step, through the detection of the speed by which the wire enters the rolling cassette, as well as the diameter and exit speed.

[57] The output diameter of the wire, for each intermediate step, corresponds to the input diameter of the next step.

[58] In any case, the method can be based on the principle of continuity of material flow, particularly of mass and, essentially equivalently, of volume per unit time, applicable to any section of the apparatus and, in particular, to the inlet and outlet section of each cassette.

[59] In practice, in the presence of a plurality of rolling cassettes, the method allows the wire inlet diameter to each rolling cassette to be worked out by proceeding backward for the same instant from the calculation of the wire inlet diameter for the terminal rolling cassette.

[60] Alternatively, it is possible to proceed in reverse, i.e., forward, by processing the wire outlet diameter from each rolling cassette for the same instant from the calculation of the wire outlet diameter for the rolling cassette at the inlet station.

[61] According to a particular aspect of the method according to the invention, it is also possible to adjust each rolling cassette independently, based on the reduction parameters, calculated for the same cassette. The wire, for example, is drawn at different speeds at each step of the process and therefore may require different adjustment controls.

[62] More specifically, the processing unit is configured to control the actuation of at least one drive member, and preferably each drive member, that drives the opening or closing of the rolling wheels, within each rolling cassette and/or the actuation of at least one drive member associated with a drawing terminal and/or intermediate unit, to vary the wire speed in the rolling process, particularly in the process step where a deviation between the reference value and the actual value is detected.

[63] Continuous processing of the inlet or outlet diameter in each cassette, terminal or intermediate, and, consequently, of the respective reduction ratio avoids the danger of the apparatus working under conditions that can cause damage, even breakage, of the wire.

[64] According to a prerogative of the invention, in fact, the method provides for implementing, by means of the aforementioned processing unit, a feedback adjustment of at least one rolling cassette, preferably of each rolling cassette, if the calculated value, of inlet diameter, or outlet diameter and/or respective reduction ratio is not within a certain allowable range or if it exceeds a threshold maximum value, for the respective reduction step within the rolling process.

[65] Such adjustment can be made automatically, thanks to the processing unit, which is in fact properly configured, to send correction signals to the drive members concerned, so as to automatically correct the opening of the rolling wheels of one or more respective rolling cassettes.

[66] More precisely, in case a correction is required, the processing unit sends a command signal to at least one drive member that drives the mutual approach or departure of the said wheels.

[67] Therefore, the method according to the invention allows the rolling process to be continuously adjusted so as to avoid waste and ensure that the required tolerances are met.

[68] Specifically, the method avoids wire breakage by adjusting the process so that wire reduction during rolling is evenly distributed.

[69] The method according to the invention and the apparatus implementing it are therefore very advantageous for monitoring and adjusting production parameters of wires or, more generally, of irregularly and variably shaped sections, e.g., improved adhesion wires for reinforced concrete, as it allows effective and preferably continuous determination of a dimensional, effective parameter of the wire at the terminal and intermediate stages of the process.

[70] The method thus allows fully automatic process adjustment at each rolling step. [71] Thus, the proposed method integrates the "dancer" correction characteristic of known production methods with the ability to precisely intervene on the opening of the rolling wheels while the process is running, thus without interrupting it. The "dancer" operates a wire speed compensation in the process.

[72] In addition, it allows the wire diameter to be monitored at intermediate steps, if any, while preventing the process from becoming unbalanced. In fact, the proposed method ensures proper distribution of the desired reduction and allows for an optimal setup in real time, without stopping the machine, which in turn allows the apparatus to be used at maximum performance in terms of speed, acceleration and deceleration.

[73] The consequent advantages of such automatic adjustment capability are all the more pronounced the more rolling steps are involved in the process.

[74] In fact, the proposed solution makes it possible, in the case of multi-step apparatus, to achieve maximum performance, i.e., an effective wire reduction, equal to that set by the apparatus control unit, a use of regulation by "dancer," limited to wire speed compensation, but not extended to error correction of the reduction set by the operators for each cassette, and a safe protection against the risk of wire breakage, either by excessive reduction applied to the wire or by abrupt acceleration and/or deceleration ramps.

Brief description of the drawings

[75] The details of the invention will be most evident from the detailed description of a preferred embodiment of the apparatus implementing the method of automatically adjusting a rolling process for wire, illustrated as an example in the accompanying drawings, in which:

Figures 1 and 2 show a front view and a plan view of the apparatus according to the invention, respectively;

Figures 3, 4, 5 and 6 show an enlarged view of details A, B, C and D shown in figures 1 or 2, respectively;

Figure 7 shows a diagram of the operation of a phase implemented by the same apparatus shown in Figures 1 through 6, according to a particular embodiment;

Figure 8 shows a flowchart of the operational steps of the method covered by the invention in a first embodiment;

Figure 9 shows a further flowchart of the operational steps of adjusting an intermediate step in a rolling process, according to the method covered by the invention.

Description of embodiments of the invention

[76] With particular reference to Figures 1 to 9, the apparatus for rolling metal wires F, according to the invention, has been referred to in the whole as 1 .

[77] The apparatus 1 may comprise, successively along a rolling direction L, an inlet station S1 , at which the wire F is intended to be fed in, an inlet sensing unit M1 , arranged at the inlet station S1 , for sensing inlet parameters of the wire F, a terminal rolling cassette 2_n and at least one intermediate rolling cassette 2j, for rolling the wire F, a terminal drawing unit 3_n and at least one intermediate drawing unit 3; for advancing the F wire along the rolling direction L through, respectively, the terminal rolling cassette 2_n and the intermediate rolling cassette 2j, as well as an outlet station S2 of the F wire and an outlet sensing unit M2, arranged at the outlet station S2, for detecting at least one outlet parameter of the wire F.

[78] Apparatus 1 also comprises a processing unit U, configured, for example, to receive and/or process data from the sensing units M1 , M2, particularly the input diameter and output diameter of the rolled wire F, as well as the data collected from the intermediate steps of the rolling process, as described in detail below.

[79] In the embodiment illustrated for illustrative purposes in Figures 1 through 9, apparatus 1 comprises four rolling cassettes, including one terminal rolling cassette 2_n and three intermediate rolling cassettes 2; . Different arrangements, with different numbers of cassettes, can be equally provided.

[80] Each rolling cassette 2_n, 2; comprises, in a known manner, at least one group of rolling wheels 20, preferably a pair of such groups. For example, in fact, rolling cassette 2_n, 2; may comprise a first group 21 and a second group 22 of rolling wheels 20, arranged successively in rolling direction L (see Figure 3).

[81] Each group 21 , 22 comprises preferably three rolling wheels 20, arranged at a wire passage section F, oriented substantially radially and distributed around the axis of wire F.

[82] Each rolling wheel 20, which is suitable for rolling on wire F, comprises preferably a peripheral throat, for housing the advancing wire F. Said throat is shaped appropriately, depending on the type of forming that the wheel performs in the rolling process. For example, the throat may be shaped substantially smooth, to reduce the diameter of the wire F, or it may have grooves, such that the desired ribs are formed on the outer surface of the wire F. In particular, the last group of rolling wheels 20 of the rolling process conforms a groove to form the ribs, while the previous group(s) in the succession have smooth groove wheels.

[83] The reducing or, more generally, forming action, imparted by each set of rolling wheels 20 depends on the width of the passage between them defined. This amplitude can be adjusted, for example, manually by means of a special adjusting crank 23, or automatically, by means of at least one appropriate drive member, preferably connected by means of a respective adjusting arm 24, to the group of rolling wheels 20. Provision can be made for a single drive member to be connected to both the first group of wheels 21 and the second group of wheels 22 in the same rolling cassette, so that both can be adjusted by a single adjusting action or, alternatively, for each group 21 , 22 to be adjusted independently (see Figures 3 and 4).

[84] Each drawing unit 3_n, 3; is preferably made by a cabestan device comprising a drive wheel 30, driven by a respective drive member 31 _n, 31 i . In a known manner, the wire F to be drawn is wound for one or more turns around the drive wheel 30 (see Figures 2 and 4). The adhesion of the wire F to the drive wheel 30 of the cabestan device, by driving member 31 _n, 31 i, ensures that the wire F advances in the rolling direction L.

[85] To compensate for any speed variations between one rolling step and the next, apparatus 1 can usefully comprise a compensating device 4. The compensating device 4 can advantageously be arranged downstream of the drawing unit 3_n, 3j, such as before the next rolling cassette 2_n, 2j, if provided.

[86] The compensation device 4, usually called a "dancer," comprises a compensation roller 40 mounted on a tilting arm 41 , rotatable about an axis parallel to the axis of rotation of the drive wheel 30 of the drive unit 3_n, 3; . The compensation roller 40 is positioned to engage the wire F and keep it in tension by means of counteracting means, such as elastic type, acting on the tilting arm 41 (see Figures 2 and 4).

[87] The inlet sensing unit M1 may have the function of detecting the input diameter Dj_n of wire F. For example, it may comprise a sensing device, such as an optical type, capable of detecting, preferably in a direct way, the diameter of the incoming F wire.

[88] Likewise, the outlet sensing unit M2 can have the function of detecting the output diameter Do_Ut of rolled F wire, particularly ribbed wire F. In the presence of a ribbed wire F, the output diameter D_out is expressed as the equivalent or nominal diameter.

[89] It too, like the inlet sensing unit M1 , may comprise a sensing device, such as an optical type, designed to detect, preferably in a direct way, the nominal output diameter D_out of the ribbed wire F.

[90] Alternatively, according to the particular form of embodiment shown in Figures 1 through 7, the nominal output diameter D_out of wire F can be indirectly detected. More precisely, according to this particular form of embodiment, the method derives the nominal outgoing diameter D_out of wire F by exploiting the principle of constancy of the flow of material, that is, wire F, which, at the same instant and for each instant, enters through input section S1 and exits through section S2.

[91] In such a case, the sensing unit M1 is configured to detect input parameters of the wire F, in particular a first input parameter and a second input parameter, to transmit them to the processing unit U of apparatus 1 to process the nominal output diameter D_out.

[92] The input sensing unit M1 comprises, in this case, preferably a first input parameter sensing device 5 and a second input parameter sensing device 6. The aforementioned first and second devices 5, 6 are usefully arranged at the inlet station S1 (see Figures 1 and 2).

[93] Preferably, the first input parameter is the input speed Vj_n of wire F. For this purpose, the first sensing device 5 is realized, for example, by at least one pair of sensing wheels 51 , 52, arranged to engage the wire F from opposite sides to the line of advance of the same wire F.

[94] Sensing means of a known type, such as an encoder, can be associated with at least one of the sensing wheels 51 , 52, to detect the input speed Vj_n of wire F (see Figure 6). For example, the first sensing device 5 may comprise two pairs of sensing wheels 51 , 52, as in the case illustrated for example in the figures. Equivalent means can be used, to detect the input velocity Vj_n of wire F.

[95] Preferably, the second input parameter is the input diameter Dj_n of wire F. For this purpose, the second sensing device 6 is made, for example, by an optical obscuration sensor or other similar means of sensors designed to detect the input diameter Dj_n of wire F as it passes through inlet station S1 (see Figure 1 ).

[96] The outlet sensing unit M2 comprises an output sensing device 7, configured to detect at least a first parameter at the output of wire F, at the outlet station S2, a second parameter at the output being detected by the same sensing group or calculated by the processing unit U, as described below.

[97] The first output parameter detected by the outlet sensing unit M2 is preferably the output speed Vo_Ut of wire F. For this purpose, the output sensing device 7 is preferably made of pairs of sensing wheels 71 , 72, similar to the sensing wheels 51 , 52 of the first sensing device 5 described above.

[98] Alternatively, equivalent means for detecting the speed of the F wire may be provided, such as means of direct detection through laser measurement. For example, apparatus 1 may comprise a sensor device associated with the drawing member 31 _n of the terminal drawing unit 3_n, configured to detect the V_out of wire F through the drawing speed imposed by the drawing wheel 30 arranged downstream of the terminal rolling cassette 2_n of apparatus 1.

[99] As another example, the aforementioned sensor device can be associated with the support frame of the aforementioned drive member to detect either the strain or the electrical absorption, as data that can be correlated, by means of the processing unit U, with the output speed V_outof the wire F.

[100] Again, particularly in the case of a ribbed wire F, the output speed V_outof the wire F can be accurately detected on at least one of the rolling wheels 20 of the last group 22 of wheels of the terminal rolling cassette 2_n, i.e., of the last rolling step, by means of a respective sensor device, e.g., encoder type, associated with it. Indeed, such a wheel 20 has a rib forming groove and, therefore, engages the forming wire F by "engaging" in it like a gear wheel on the respective rack. Because of this, the aforementioned wheel 20 essentially does not slip on the wire F, but rotates at the same speed as the wire F, which therefore represents an essentially correct measure of the output speed V_out.

[101] The output sensing device 7 or such equivalent means are configured to send the sensed data to the processing unit U for it to process, preferably continuously, the output diameter Do_Ut of the rolled wire F through the equivalent diameter calculation. In practice, the processing unit U can process the output diameter D_out from the constancy of the flow of material F through the input S1 and output S2 stations, expressed by the following equation:

D² _in* V_in= D² _0Ut* Vout

[102] In addition, processing unit U can also process the total reduction ratio that the process realizes between inlet station S1 and outlet station S2, according to the following formula:

R% = (1 - Dg_Ut/D _n )xl00.

[103] When the apparatus 1 comprises only one rolling cassette, if the output diameter D_out of the rolled wire F and/or, equivalently, the reduction ratio R% do not correspond to the desired values, the processing unit U is configured to send commands so that by the operation of at least one respective drive member, the opening or closing of the rolling wheels 20 is adjusted and the aforementioned parameters are brought within a permissible tolerance range.

[104] If, on the other hand, the apparatus 1 is a multi-step type, thus comprising a plurality of rolling cassettes in succession, as in the case illustrated in Figures 1 to 7, the processing unit U is preferably configured to automatically adjust the partial or intermediate percentage reduction R%i, carried out in each intermediate step, to realize overall reduction of wire diameter F from Dj_nto D_outand control its correct distribution.

[105] In practice, the processing unit U can determine a distribution, for example a balanced distribution, of the total percent reduction value over the process steps by calculating a reference value R%i_ref for the intermediate percent reduction R%Jn each step.

[106] The method then involves calculating the actual value of the intermediate percent reduction R%j and comparing it with the aforementioned reference value. Alternatively, the method can compare the actual value of the intermediate output diameter Dj__out , preferably for each step, with a reference intermediate output diameter.

[107] More precisely, according to a first embodiment, the processing unit U is configured to process the intermediate inlet diameter Djj_n of the wire F, entering each intermediate rolling cassette 2; of the rolling apparatus 1 , based on the above-mentioned principle of material flow constancy, from the knowledge of the output diameter Dj__out of wire F, the output speed Vj__out and the input speed Vjj_n of wire F in the same intermediate rolling cassette. These data, i.e., the intermediate input diameters Djj_n of the intermediate steps, can be calculated backward from the terminal rolling cassette 2_n, for which the diameter and output speed are taken by the outlet sensing unit M2 and/or calculated by the processing unit U, as described above. The same output data from wire F can also be input to processing unit U, for example, at a given frequency.

[108] Similarly, for a second alternative embodiment, the processing unit U can be configured to process the intermediate output diameter Dj__out of the wire F exiting each intermediate rolling cassette 2; of the rolling apparatus 1 , based on the aforementioned principle of material flow constancy, from knowledge of the input diameter Djj_n of wire F, the output speed Vi out and the input speed Vjj_n of wire F in the same intermediate rolling cassette. These data can be calculated in logical succession, starting from the first rolling cassette 2j, for which the diameter and the output speed can be taken, for example, from the inlet sensing unit M1 or, for example, input to the processing unit U, for example, at a given frequency.

[109] In what follows, reference will be made to the first embodiment, meaning the second embodiment will also be described by analogy.

[110] In what follows, reference will be made to the first embodiment, meaning the second embodiment will also be described by analogy.

[111] For each step, therefore, the calculated or measured input, diameter and wire speed data correspond to the output data of the previous cassette along the rolling cassette direction L and thus serve as the basis for calculating the corresponding intermediate input diameter Dj j_n. In practice, it can be considered that between one step and the next, the wire has an intermediate diameter Dj that coincides with the output diameter of the previous step and the input diameter of the next step, for wire F.

[112] Preferably, a sensor device is usefully connected to each drive member 31 _n, 31; that drives the rotation of a respective drawing wheel 30, to detect a data item related to the intermediate speed of wire F. This speed is indicative of both the input speed V_L j_n of wire F into the rolling cassette arranged downstream of it and the output speed Vj-i__out of the previous step. This speed data is therefore preferably sent continuously to the processing unit U.

[113] Similarly as described above, the processing unit U is configured to calculate the inlet diameter Djj_n of wire F in each intermediate rolling cassette 2, based on the principle of continuity of the flow of wire F, in and out through the i-th rolling cassette, according to the formula: j out

[114] In practice, starting from the knowledge of the output diameter D_out from the last rolling step, either directly or indirectly detected, or input, as described above, the processing unit U is thus able to calculate the input diameter Djjn at any intermediate step. [115] The processing unit U is also preferably and advantageously configured to calculate the actual value of percentage reduction in each intermediate rolling cassette:

Ri% = - Dl_out/Dl_in )xl00

[116] The processing unit U can also be advantageously configured to compare this actual reduction value R%i of each rolling cassette with the respective reference value R%i_ref, such that an effective, preferably balanced, distribution of the total reduction, i.e., the total reduction between the input diameter Dj_n and the output diameter D_out of the wire F passing through the rolling apparatus 1 can be achieved.

[117] Advantageously, the unit U is configured to automatically adjust the operating parameters, preferably of each rolling cassette 2_n, 2j .

[118] More specifically, the processing unit U is configured to compare the actual value of the intermediate diameter Dj or intermediate reduction R%j with the respective reference value, Dj ref or R%j__ref, and, if there is a deviation or if the deviation is outside a reference range, the processing unit U is configured to send an adjustment command to the rolling cassette 2_n, 2; concerned, aimed at acting, by operation of the appropriate drive member, on the opening of the rolling wheels 20. Such an adjustment command, therefore, directly modifies the intermediate reduction ratio R%i and thus results not only in a change in the intermediate output diameter Dj__out, but also in a change in the corresponding intermediate output speed Vj__out.

[119] The respective compensation device 4 can intervene in such a circumstance, keeping the wire F in tension by swinging the tilting arm 41 bearing the compensation roller 40.

[120] In practice, rolling apparatus 1 is able to self-adjust, going to change the actual reduction and thus the actual diameters exiting each rolling cassette 2_n, 2j, by acting on the drive members that control the opening of the rolling wheels 20.

[121] The operation of the rolling apparatus according to the invention is easily understood from the above description.

[122] Wire F is dragged through the inlet station S1 of apparatus 1 , the inlet sensing unit M1 , and rolling cassettes 2_n, 2i, by the actuation of drawing units 3_n, 3(i> .

[123] Therefore, the wire F is rolled and, in particular, ribbed by the action of the rolling wheels 20 of the rolling units 21 , 22, rolling cassettes 2_n, 2j, passing through the outlet station S2 and, therefore, the outlet sensing unit M2.

[124] At inlet station S1 , inlet sensing unit M1 detects the input velocity Vj_n and input diameter Din of wire F. At the same time, outlet sensing group M2 detects the output velocity V_out of wire F and possibly the output diameter D_out.

[125] Both the input and output parameters of wire F are therefore transmitted to the processing unit U, which, in case the data is not directly detected or input, processes, therefore, the output diameter D_outof wire F. [126] More precisely, the processing unit U can calculate the above parameter due to the flow continuity principle, i.e. , for each instant, the constancy of the mass M of wire F per unit time t at the input M_n and output M_out through, respectively, inlet station S1 and outlet station S2: M_0Ut/t=M_0Ut/t

[127] In practice, the processing unit U can calculate the output diameter D_out of the wire F through the following formula:

[128] Alternatively, the outlet sensing unit M2 can directly detect the output diameter D_out of wire F using a special device and send the corresponding signal to the processing unit U.

[129] The processing unit U can also process the total effective reduction ratio between inlet station S1 and said outlet station S2, according to the following formula:

R% = (1 - Dg_Ut/D _n )xl00.

[130] The processing unit U can also process a preferably balanced distribution of the total reduction ratio R% between inlet station S1 and outlet station S2, for example, by calculating reference intermediate reduction values R%i_ref, or values reference intermediate diameters Dj__ref, preferably for each step.

[131] During the rolling process, the processing unit U receives, either essentially continuously or at a given frequency, intermediate data, indicative of the intermediate speed of the wire, for example, transmitted by the drive members 31 _n, 31 i of the draw wheels 30 at each step. These data are normally different, by virtue of the progressive reduction in wire diameter F at each step.

[132] Through this input data and the output diameter data D_out of wire F, measured, either directly or indirectly, by the input and outlet sensing units M1 , M2, the processing unit U processes the intermediate input diameter Djjnfor each intermediate rolling cassette 2j.

[133] Such processing allows for processing, then monitoring, preferably continuously, of the reduction ratio actually R%i applied on the wire F by the intermediate rolling cassette 2_S.

[134] The processing unit U compares that intermediate reduction ratio R%j with a reference value R%j_ref or a reference range. Alternatively, the processing unit U can directly compare the calculated intermediate diameters Dj with reference values. In case of deviation, the processing unit U sends an automatic adjustment command to the drive member that changes the opening of the rolling wheels 20 to concordantly vary the inlet diameter and outlet diameter through the respective rolling step.

[135] The compensating device 4 in the step in question can cooperate in the adjustment by automatically rotating the tilting arm 41 to constantly maintain the tension of the wire F.

[136] Therefore, the rolling apparatus according to the invention, which implements the described method, allows for continuous monitoring of the rolling process, ensuring that it takes place in a balanced way through the rolling cassettes. [137] The apparatus described as an example is subject to many modifications and variations according to different needs.

[138] In the practical implementation of the invention, the materials used, as well as the shape and size, can be any as needed.

[139] Where the technical features mentioned in each claim are followed by reference marks, such reference marks have been included for the sole purpose of increasing the understanding of the claims and consequently they have no limiting value on the purpose of each element identified by way of example by such reference marks.

Claims

1. A method for automatically adjusting a process for rolling metal wires, particularly cold rolling, by means of a rolling apparatus, comprising the steps of ao. setting up a processing unit (U) of said rolling apparatus; a. feeding along a rolling direction (L) a wire (F) through, in succession, an inlet station (S1 ), a plurality of rolling cassettes (2_n, 2j), each representing a rolling step of said process and comprising at least one group (21 , 22) of rolling wheels (20), defining between them a passage for said wire (F), for reducing the diameter of said wire (F) from an inlet diameter (Dj_n) to an outlet diameter (Do_Ut) through at least one intermediate diameter (Dj) between a process step and a subsequent process step, and an outlet station (S2) of said apparatus (1 ), said plurality of rolling cassettes comprising a terminal rolling cassette (2_n) or terminal step, at the exit from which said wire (F) has said outlet diameter (D_out), and at least one intermediate rolling cassette (2j) or intermediate step which, starting from said inlet station (S1 ) precedes said terminal rolling cassette (2_n) along said rolling direction (L), said wire (F) being fed along said rolling direction (L) by means of a terminal drawing unit (3_n) arranged downstream of said terminal rolling cassette (2n) and at least one intermediate drawing unit (3j) arranged downstream of said intermediate rolling cassette (2i); b. detecting and/or inputting at least one pair of data, indicative of said inlet diameter (Dj_n) and said outlet diameter (D_out) respectively, and/or process by means of said processing unit (U) of said apparatus (1 ) a total percentage reduction value (R%) of the diameter of said wire (F) between said inlet station (S1 ) and said outlet station (S2), expressed by the formula:

R% = (1 - (D_out)²/(D_f)²)xl00 or directly enter said total percentage reduction value (R%) into said processing unit (U); c. processing by means of said processing unit (U) a reference value of intermediate percent reduction (R%j__ref) or intermediate diameter (Dj__ref), for at least one intermediate step of said process, distributing the reduction of said diameter of said wire (F) among said steps of said process; d. detecting by means of a sensor device at least one intermediate datum, indicative of an intermediate speed (Vj__Out, Vjj_n) and/or an intermediate percentage reduction (R%i) of said wire (F), drawn through a said intermediate step; e. transmitting said at least one said intermediate data to said processing unit (U); f. calculating an effective value of intermediate percentage reduction (R%i) or an effective value for said intermediate diameter (Di, Djj_n, Di__out) of said wire (F); g. comparing by means of said processing unit (U) said actual value with said reference value (R%j__ref, Di__ref) and, in case of deviation; h. sending, through said processing unit (U), an adjustment command, so as to vary the amplitude of said passage for said wire (F) and/or the speed (V_out, Vin, Vi out, Vj in) of said wire (F), in said process.

2. The method of claim 1 , wherein said step h. of sending an adjustment command involves sending said adjustment command to at least one drive member connected to said rolling wheels (20) of at least one of said rolling cassettes (2_n, 2j) to move them, so as to vary the width of said passage for said wire (F).

3. The method of claim 1 or 2, wherein said step h. of sending an adjustment command involves sending said adjustment command to a drive member (31 _n, 31 i) of at least one said drawing unit (3_n, 3j) to change the speed of said wire (F) through said rolling cassette (2_n, 2j), according to said detected deviation and/or said adjustment signal sent to said drive member connected to said rolling wheels (20).

4. The method of any one of the preceding claims, wherein said step f.) of calculating said actual value of intermediate percent reduction (R%i) or said actual value of intermediate diameter (Di) provides for the step of detecting also the exit velocity (V_out) of said wire (F) at said outlet station (S2) and calculating said intermediate inlet diameter (Dij_n) at said intermediate rolling cassette (2j), by the following formula, an expression of the continuity of wire flow (F):

5. The method of any one of the preceding claims, wherein said apparatus comprises a plurality of said intermediate rolling cassettes (2j) preceding along said rolling direction (L) said terminal rolling cassette (2_n), said method providing for the further step of calculating a said intermediate inlet diameter (Dij_n) at each further said intermediate rolling cassette (2j) by applying the formula: and considering as the intermediate output diameter (Di__out) and intermediate output speed (Vj out) of said additional intermediate rolling cassette (2i) the respective input values (Dij_n, Vj_in) either detected or calculated, referring to a said immediately following intermediate rolling cassette along said rolling direction (L).

6. The method of any one of the preceding claims, wherein said sensor device is associated with a drive member (31 i) of a said intermediate drawing unit (3j) and/or a support of said drive member (31 i) and/or said rolling cassettes (2j) and/or a speed compensation device (4), acting on said wire (F), and/or a said rolling wheel (20), to detect in particular a strain or electrical absorption.

7. An apparatus for rolling metal wires, comprising an inlet station (S1 ) and an outlet station (S2) for a said wire (F) to be rolled according to a rolling direction (L), a plurality of rolling cassettes (2_n, 2j), each comprising at least one group (21 , 22) of rolling wheels (20), defining between them a passage for said wire (F), at least one drive member being connected to said rolling wheels (20) to move them, so as to vary the width of said passage, said plurality of rolling cassettes (2_n, 2j) being interposed between said inlet station (S1 ) and said outlet station (S2), to reduce the diameter of said wire (F) from an inlet diameter (Dj_n) to an outlet diameter (D_out) through at least one intermediate diameter (Dj) between one process step and a subsequent process step, said plurality comprising a terminal rolling cassette (2_n) or terminal step, at the exit of which said wire (F) has said outlet diameter (D_out) and at least one intermediate rolling cassette (2j) or intermediate step which, starting from said inlet station (S1 ), precedes said terminal rolling cassette (2_n) along said rolling direction (L), a terminal drawing unit (3_n) and, respectively, an intermediate drawing unit (3j), each being driven by a respective drive member (31 _n, 31 i) to drive forward said wire (F) in said rolling direction (L) along at least one respective terminal and/or intermediate rolling cassette (2_n, 2j), a sensor device configured to detect an intermediate datum indicative of an intermediate speed (Vj__out, Vjjn) of said wire (F) pulled through a said intermediate step, and a processing unit (U), configured to receive and process said intermediate data detected by said sensor device and process an actual value of intermediate percentage reduction (R%i) or intermediate diameter (Dj), compare by means of said processing unit (U) said actual value with a reference value of intermediate percent reduction (R%j__ref) or intermediate diameter (Dj__ref).

8. The apparatus of claim 7, wherein said processing unit (U) is configured to send, in case of deviation between said actual value and said reference value, an adjustment command to at least one said drive member connected to said rolling wheels (20) of at least one of said rolling cassettes (2_n, 2j) to move them, so as to vary the width of said passage for said wire (F).

9. The apparatus of claim 7 or 8, wherein said processing unit (U) is configured to send, in case of deviation between said actual value and said reference value, an adjustment command to at least one said drive member (31 _n ,31 i) of at least one said drive member (3_n, 3j) to change the speed of said wire (F) through said rolling cassette (2_n, 2j), according to said detected deviation and/or to a said adjustment signal sent to said drive member connected to said rolling wheels (20).

10. The apparatus of any one of claims 7 to 9, wherein said sensor device is associated with a said drive member (31 i) of said intermediate drawing unit (3j) and/or a support of said drive member (31 i) and/or said rolling cassettes (2j) and/or a speed compensation device (4), acting on said wire (F), and/or a said rolling wheel (20), to detect in particular a strain or electrical absorption.

11. The apparatus of any one of claims 7 to 10, wherein it comprises an additional sensor device, associated with at least one of said rolling wheels (20) of a last group (22) of wheels of said terminal rolling cassette (2_n), presenting a peripheral rib throat, said sensor device being configured to detect the rotational speed of said wheel (20), as an indicative value of the output speed (V_out) of said wire (F) from said terminal rollingg cassette (2_n).

12. The apparatus of any one of claims 7 to 11 , wherein said processing unit (U) is configured to process said actual value of the intermediate diameter (Di, Djj_n, Dj__out), by means of the following formula, an expression of the continuity of wire flow (F):